Effects of tire chips on shrinkage and cracking characteristics of cohesive soils

Some important engineering characteristics of compacted clay liners can be adversely affected by desiccation cracking, resulting in the loss of effectiveness and integrity of containment systems as a barrier. Recently, there has been interest in using tire chips as an additive material to prevent desiccation cracking. In this study, compaction, shrinkage, and desiccation cracking tests were performed to study the effect of tire chips on suppressing shrinkage and desiccation cracks in clayey soils. The percentages of tire chips used were 10%, 20%, and 30% by weight. The results of shrinkage tests indicate that the percentage of volume change of the specimens decreases with addition of tire chips and its value also is affected by size of the tire chips. The intensity of cracks diminishes in the clay–tire mixtures so that the observed crack reduction in the range of used tire chips content is about 40% to 80%. The optimum tire chips content also is necessary to achieve maximum crack reduction and minimum shrinkage strain, while maintaining acceptable hydraulic conductivity. This study suggests the potential application of waste tires to suppress desiccation cracks encountered in landfill clay liners.